Now, Alex, I realize that government may be required to offer alternatives to people who insist on doing something dumb, but do churches have to do that, too?

Only if they care about people dying. It's all too obvious they don't.

If a church tells its members to practice only monogamous sex, is it bound to offer alternatives for those who prefer not to be monogamous?

Only if they care about people dying. Clearly they don't.

Can't they let the non-monogamists figure things out on their own?

If they don't give a fuck about people dying, I guess they can. And obviously they don't.

Compassionate humans would care more than about their rules being followed; they'd care about what happens to people who don't follow their rules. But the RCC doesn't give a flying fuck about that. If you don't follow our rules, die for all we care. And people do. And you don't care.